1Ti 3:15 but if I am delayed, I write so that you may know how you ought to conduct yourself in the house of God, which is the church of the living God, the pillar and ground of the truth.
The Church is the pillar and ground of the truth in this sense---the Church is the upholder and proclaimer of the truth of the Gospel and of the Lord Jesus Christ.
As the ground and a pillar support and uphold something, so does the Church uphold the truth of the Gospel and the Lord Jesus Christ.
As a pillar was used during Paul's time to post and advertise notices for the public to see, so the Church proclaims the truth of the Gospel and the Lord Jesus Christ.
